While our understanding of the genetic and neurobiological factors that contribute to attention and learning problems in children has grown sharply, ADHD remains a significant public health concern. Its high prevalence, associated and variable morbidity, and frequent chronicity make ADHD difficult for a single health or mental health provider to diagnose and treat. However, multimodal and multidisciplinary care is expensive and may be unavailable for many children, despite standards of practice calling for such care. Coincident with the growth of managed care and changes in special education policies, the prevalence of stimulant treatment for ADHD in North America has increased dramatically, accompanied by a shift from subspecialist care to predominantly care by primary care physicians. Although psychosocial services such as psychological testing, parent training and school consultation are often available, it is unclear how often stimulant treatment is augmented or coordinated with these psychosocial services. Moreover, despite the fact that the majority of ADHD treatment is provided in primary care, very little research on ADHD is conducted in primary care settings. The primary focus of this proposal is to address the following goals: 1) describe the service utilization patterns and effectiveness of ADHD treatment provided in primary health-care settings; 2) develop and pilot pharmacotherapy and psychosocial treatments to improve ADHD management in primary care settings; and 3) develop clinical research settings in primary care to provide representative samples for clinical trials and genetic research on ADHD. Helping link advances in neurobiology and genetics with clinical practice, the ultimate goal is to increase the effectiveness of ADHD treatment in usual practice settings. Mark A. Stein has considerable clinical and research experience with ADHD. This proposal would enable Mark Stein to develop further his skills to conduct cost-effectiveness studies in primary care settings, and maintain his ongoing research program on the etiology, differential diagnosis, and pharmacological treatment of ADHD. With the support of CNMC, the candidate will mentor junior faculty from psychology, psychiatry, pediatrics, and neurology interested in ADHD research.